[erlang-questions] Any Erlang GIS software out there?

[Anthony Molinaro]

On Wed, Dec 14, 2011 at 01:17:27PM +0100, Dave Cottlehuber wrote:
> On 15 September 2011 18:06, Anthony Molinaro
> <anthonym@REDACTED> wrote:
> >  I'm interested in doing some reverse geocoding (taking lat/long and
> > getting nearby cities).  While looking around I've not seen any GIS
> > related software written in erlang.  So just wondering if I'm missing
> > anything?  Anyone written any GIS related software in Erlang?
> 
> GeoCouch https://github.com/couchbase/geocouch by Volker Mische is a
> popular erlang extension to CouchDB that does GIS stuff such as
> bounding box queries. You would need to have the list of interesting
> stuff such as cities in the Couch DB already.

Thanks for the pointer, but the trick is the interesting stuff, which
AFAIK is not readily available (ie, city bounding box data is not
easily available, even country data is not readily available as far
as I can tell).  I ended up solving this issue by using a nearest
neighbor type of setup, where I had the latitude and longitude of a
number of cities (about 60K cities), so created an ets table which
I could query using a bounding box around the current latitude and
longitude then calculating the distance to all the points in the box
and minimizing.  The nice thing about this is its very fast, is very
little code and easily fits in memory on a box.

Cheers,

-Anthony

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Anthony Molinaro                           <anthonym@REDACTED>